Hiroki Shimizu

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Adaptor proteins, with multimodular structures, can participate in the regulation of various cellular functions. A novel adaptor protein XB130 has been implicated as a substrate and regulator of tyrosine kinase-mediated signaling and in controlling cell proliferation and apoptosis in thyroid and lung cancer cells. However, its expression and role in(More)
Coupling of glycosylated Fmoc-Thr or Fmoc-Ser with N-terminal amino acids on a resin proceeded smoothly under microwave irradiation for 20 min with much higher efficiency (98% yield per coupling) than found in more general conditions. Compared with a conventional protocol, the present method greatly reduces the time required for solid-phase glycopeptide(More)
Microwave-assisted solid-phase synthesis allows for the rapid and large-scale preparation and structure-activity characterization of tandem repeating glycopeptides, namely monodispersed synthetic antifreeze glycopeptides (syAFGPs, H-[Ala-Thr(Galβ1,3GalNAcα1→)-Ala]n -OH, n=2-6). By employing novel AFGP analogues, we have demonstrated that of the(More)
Vibrio cholerae neuraminidase (VCNA) plays a significant role in the pathogenesis of cholera by removing sialic acid residues from higher-order gangliosides to an unmasked GM1, the essential receptor for cholera toxin. Here we report that a novel mechanism-based fluorescent labeling reagent,(More)
We report the thermodynamics of binding of d-galactose and deoxy derivatives thereof to the arabinose binding protein (ABP). The "intrinsic" (solute-solute) free energy of binding DeltaG degrees (int) at 308 K for the 1-, 2-, 3-, and 6-hydroxyl groups of galactose is remarkably constant (approximately -30 kJ/mol), despite the fact that each hydroxyl group(More)
Aquaporins (AQPs) are water channel proteins that facilitate transcellular water movements. Recent studies have shown that AQP5 is expressed in various cancers, and plays a role in tumor progression. However, its expression and role in esophageal squamous cell carcinoma (ESCC) have not been investigated. We examined the pathophysiologic role of AQP5 in cell(More)
xCT is a component of the cysteine/glutamate transporter, which plays a key role in glutathione synthesis. The objectives of the present study were to investigate the role of xCT in the regulation of genes involved in cell cycle progression and the clinicopathological significance of its expression in esophageal squamous cell carcinoma (ESCC). xCT(More)
BACKGROUND This study was designed to evaluate the clinical significance of undifferentiated component in differentiated T1/T2 gastric adenocarcinoma. METHODS Two hundred thirty-one patients who underwent curative gastrectomy were diagnosed pathologically as differentiated type T1/T2 gastric cancer according to Japanese Classification of Gastric Carcinoma(More)
AIM To evaluate the clinicopathological features of mixed-type gastric cancer and their influence on prognosis of mixed-type stage I gastric cancer. METHODS We analyzed 446 patients who underwent curative gastrectomy for stage I gastric cancer between 1999 and 2009. The patients were divided into two groups: those with differentiated or undifferentiated(More)
AIM To investigate the role of claudin 1 in the regulation of genes involved in cell migration and tumor necrosis factor alpha (TNF-α)-induced gene expression in human gastric adenocarcinoma cells. METHODS Knockdown experiments were conducted with claudin 1 small interfering RNA (siRNA), and the effects on the cell cycle, apoptosis, migration and invasion(More)